InGaP/GaAs hole barrier asymmetry determined by (002) X-ray reflections and p-type DB-RTD hole transport

InGaP/GaAs heterostructures are grown by LP-MOVPE. The InGaP layer embedded in GaAs and both the upper and the lower interface are characterized by high resolution X-ray diffraction (HR-XRD) using the (002) reflection, which is quasi forbidden for GaAs. Thin and center-symmetric InGaP-GaAs-InGaP structures embedded in GaAs result in fringes which can be described using kinematical theory. This way both a thickness and composition analysis of InGaP layers is analytically obtained. Under optimized growth conditions the GaAs-to-InGaP interface is atomically abrupt while a 1 ML InGaAs interfacial layer is determined at the InGaP-to-GaAs interface. This asymmetry results in different hole-barrier functionality which is proven by low temperature I-V-characterization of p-type double barrier resonant tunneling diode (DB-RTD). (C) 1998 Elsevier Science B.V. All rights reserved.